ID   PSBI_PROMP              Reviewed;          42 AA.
AC   Q7V339;
DT   21-AUG-2007, integrated into UniProtKB/Swiss-Prot.
DT   01-OCT-2003, sequence version 1.
DT   25-MAY-2022, entry version 94.
DE   RecName: Full=Photosystem II reaction center protein I {ECO:0000255|HAMAP-Rule:MF_01316};
DE            Short=PSII-I {ECO:0000255|HAMAP-Rule:MF_01316};
DE   AltName: Full=PSII 4.4 kDa protein {ECO:0000255|HAMAP-Rule:MF_01316};
GN   Name=psbI {ECO:0000255|HAMAP-Rule:MF_01316}; OrderedLocusNames=PMM0253;
OS   Prochlorococcus marinus subsp. pastoris (strain CCMP1986 / NIES-2087 /
OS   MED4).
OC   Bacteria; Cyanobacteria; Synechococcales; Prochlorococcaceae;
OC   Prochlorococcus.
OX   NCBI_TaxID=59919;
RN   [1]
RP   NUCLEOTIDE SEQUENCE [LARGE SCALE GENOMIC DNA].
RC   STRAIN=CCMP1986 / NIES-2087 / MED4;
RX   PubMed=12917642; DOI=10.1038/nature01947;
RA   Rocap G., Larimer F.W., Lamerdin J.E., Malfatti S., Chain P., Ahlgren N.A.,
RA   Arellano A., Coleman M., Hauser L., Hess W.R., Johnson Z.I., Land M.L.,
RA   Lindell D., Post A.F., Regala W., Shah M., Shaw S.L., Steglich C.,
RA   Sullivan M.B., Ting C.S., Tolonen A., Webb E.A., Zinser E.R.,
RA   Chisholm S.W.;
RT   "Genome divergence in two Prochlorococcus ecotypes reflects oceanic niche
RT   differentiation.";
RL   Nature 424:1042-1047(2003).
CC   -!- FUNCTION: One of the components of the core complex of photosystem II
CC       (PSII), required for its stability and/or assembly. PSII is a light-
CC       driven water:plastoquinone oxidoreductase that uses light energy to
CC       abstract electrons from H(2)O, generating O(2) and a proton gradient
CC       subsequently used for ATP formation. It consists of a core antenna
CC       complex that captures photons, and an electron transfer chain that
CC       converts photonic excitation into a charge separation.
CC       {ECO:0000255|HAMAP-Rule:MF_01316}.
CC   -!- SUBUNIT: Cyanobacterial PSII is composed of 1 copy each of membrane
CC       proteins PsbA, PsbB, PsbC, PsbD, PsbE, PsbF, PsbH, PsbI, PsbJ, PsbK,
CC       PsbL, PsbM, PsbT, PsbX, PsbY, PsbZ, Ycf12, at least 3 peripheral
CC       proteins PsbO, PsbU, PsbV and a large number of cofactors. It forms
CC       dimeric complexes. {ECO:0000255|HAMAP-Rule:MF_01316}.
CC   -!- SUBCELLULAR LOCATION: Cellular thylakoid membrane {ECO:0000255|HAMAP-
CC       Rule:MF_01316}; Single-pass membrane protein {ECO:0000255|HAMAP-
CC       Rule:MF_01316}.
CC   -!- SIMILARITY: Belongs to the PsbI family. {ECO:0000255|HAMAP-
CC       Rule:MF_01316}.
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DR   EMBL; BX548174; CAE18712.1; -; Genomic_DNA.
DR   RefSeq; WP_002805124.1; NC_005072.1.
DR   AlphaFoldDB; Q7V339; -.
DR   SMR; Q7V339; -.
DR   STRING; 59919.PMM0253; -.
DR   EnsemblBacteria; CAE18712; CAE18712; PMM0253.
DR   KEGG; pmm:PMM0253; -.
DR   HOGENOM; CLU_212150_0_0_3; -.
DR   Proteomes; UP000001026; Chromosome.
DR   GO; GO:0016021; C:integral component of membrane; IEA:UniProtKB-KW.
DR   GO; GO:0009539; C:photosystem II reaction center; IEA:InterPro.
DR   GO; GO:0031676; C:plasma membrane-derived thylakoid membrane; IEA:UniProtKB-SubCell.
DR   GO; GO:0015979; P:photosynthesis; IEA:UniProtKB-UniRule.
DR   HAMAP; MF_01316; PSII_PsbI; 1.
DR   InterPro; IPR003686; PSII_PsbI.
DR   InterPro; IPR037271; PSII_PsbI_sf.
DR   Pfam; PF02532; PsbI; 1.
DR   SUPFAM; SSF161041; SSF161041; 1.
PE   3: Inferred from homology;
KW   Membrane; Photosynthesis; Photosystem II; Reaction center; Thylakoid;
KW   Transmembrane; Transmembrane helix.
FT   CHAIN           1..42
FT                   /note="Photosystem II reaction center protein I"
FT                   /id="PRO_5000096434"
FT   TRANSMEM        6..26
FT                   /note="Helical"
FT                   /evidence="ECO:0000255|HAMAP-Rule:MF_01316"
SQ   SEQUENCE   42 AA;  4796 MW;  992C2D2AF19BE3EE CRC64;
     MLALKISVYT IVFFFVGIFL FGFLASDPTR TPNRKDLESP QD